Fixing plasterboard to a stud wall

Summary: Learn how to fix plasterboard to a stud wall, fit the plasterboard, fill the joints, fill the joints for tapered-edge board, fill the joints for straight-edge board and cut the plasterboard.

Plasterboard is fixed to timber or metal stud walls. The sides of plasterboard will be different colours: usually pale grey or ivory on one side and a darker grey or brown on the reverse. When fixing plasterboard it is the lighter side that faces into the room, the darker side may carry the manufacturer’s name or logo.

Preparation

Marking the position of the timber studs on the ceiling will assist when you come to fix the sheets of plasterboard in position.

Plasterboard comes in large sheets and can be difficult to lift and manoeuvre into position particularly if you are working alone. To help lift the plasterboard up to the ceiling you can make a simple tool called a footlifter or rocking wedge. This works on the same principle as the seesaw.

A footlifter is made from a piece of softwood 250mm (10in) L x 75mm (3in) W x 50mm (2in) H. On the side of the timber block draw two straight lines from the top corners to the centre of its base. The wedge-shaped pieces are then cut away.

When fixing a sheet of plasterboard the bottom edge of the plasterboard is placed on one end of the footlifter. Then simply press down with your foot on the other end and the plasterboard will lift.

Before starting, cut all the sheets of plasterboard 15mm (5/8 in) shorter than the height of the wall.

Fixing the plasterboard

Fix all the whole boards first. If boarding a complete wall with no door, start in the corner and work across to the other corner. If boarding a wall with a door start at the door and work towards the furthest corner.

Using the footlifter raise the first board firmly against the ceiling. Remember that it is the lighter side that faces into the room.

Apart from the boards at the ends of the wall, the edges of the boards must be aligned midway over a stud.

Nail the board around its edges and to the noggins between the studs using galvanised plasterboard nails. The size of the nail you use depends on the thickness of the board, but as a guide:

The nails should be at least 15mm (5/8 in) from the edge and 150mm (6 in) apart. Take care not to damage the board when driving the nails into the studs.

Dropping a plumb line from the marks on the ceiling indicating the position of the studs will allow you to mark the position of each stud on to the face of the board. Nail the board to each stud at 150mm (6 in) intervals.

On reaching the end of the wall measure the gap to be filled and cut a piece of board remembering that it has to butt tightly up against the adjacent wall. You may need to scribe the boards to fit against uneven walls, floors or ceilings.

Having fixed plasterboard to one side of the wall, repeat the process on the other side of the timber stud frame.

Filling the joints

When the plasterboard is fixed to the stud frame you will need to fill the joints between the boards. The method you employ will depend on whether you have used tapered-edge or square-edge boards.

Tapered-edge board

Mix up some jointing compound as indicated on the packet. A stiff mix is best for covering nail or screw heads and gaps wider than 3mm (1/8 in).

Then use a broad-blade filling knife to press the compound into the gap, spreading the compound in a thin layer covering about 25mm (1in) on either side of the gap.

Cut and stick a length of jointing tape over the first joint using the jointing compound as the adhesive. Ensure the all air bubbles are pressed out and the tape is stuck firmly to the board.

Repeat for all the other joints.

Cover the taped joints with another thin layer of jointing compound using a plasterer’s trowel or taping knife. Smooth the compound so it is flush with the surface of the board. At this stage you can also fill any screw holes.

Before the compound has dried fully, smooth over the joint with a moist jointing sponge, feathering the edges into the surface of the board and removing any excess compound. But take care not to move the tape.

When the compound has dried, apply another thin layer, but this time feathering the compound 300mm (12in) beyond the joint.

When this final layer of compound has dried, the walls can then be painted with a proprietary board sealant.

If using self-adhesive jointing tape, cut the tape to the length you require and stick it directly over the joint. Then follow the method as described above.

Straight-edge board

If using self-adhesive jointing tape, stick it directly over the joint. If using scrim tape apply mixed plaster to the joint, pressing it firmly into the narrow gap between the boards and spreading it thinly on each side of the joint to create a band of plaster about 100mm (4in) thick.

Measure and cut the scrim tape to the required length and using a trowel press it firmly against the plaster.

With the scrim tape stuck in place over the joint, spread a thin layer of plaster over the whole length of the tape.

Repeat this process for all the joints.

Cutting plasterboard

When fixing plasterboard, it is inevitable that you will need to cut some of the boards to fit.